Chickenpox Vaccine
The Issue
There are new recommendations about who should get the chickenpox vaccine. Talk to your doctor or health care provider about the benefits of this vaccine for members of your family who are at least 12 months old, and have never had chickenpox.
Background
Chickenpox (varicella) is caused by a virus called Varicella-zoster. It starts with a fever and is followed by a rash of red spots that may be itchy. There may be hundreds of these spots, which eventually turn into blisters filled with fluid. After four or five days, the blisters dry out and become crusted. From start to finish, chickenpox may last seven to ten days.
The virus spreads easily and quickly through personal contact such as touching the blisters. People with chickenpox can also spread the virus through the air when they cough or sneeze. A pregnant woman can pass the chickenpox virus on to her baby before it is born.
Most adults today who grew up in Canada had chickenpox as children. It is estimated that 90% of children who are not vaccinated for chickenpox will get it by the time they are twelve. As a general rule, you can only get chickenpox once, but it's also possible for the virus to remain in your body and become active again later on. When this happens, the virus causes a painful rash of blisters called shingles.
Complications Associated with Chickenpox
Most children who get chickenpox recover completely. However, severe cases of chickenpox can pose serious health risks, especially for newborn babies, adults, or anyone with a weakened immune system.
The complications from chickenpox can include bacterial skin infections, scars (if the blisters get infected), pneumonia, and encephalitis (inflammation of the brain). There is an increased risk of birth defects for babies who get chickenpox from their mothers before birth. Also, children with chickenpox have an increased risk of getting necrotizing fasciatus/mytositis (flesh-eating disease). It should be noted, however, that while flesh-eating disease is a complication of chickenpox in children, very few children with chickenpox will develop flesh-eating disease.
Other Considerations
Chickenpox costs Canadians more than $122 million per year. This figure represents the cost of medical and hospital care, along with personal and productivity costs for parents and others who take time away from work to be caregivers.
Chickenpox Vaccine
The vaccine for chickenpox was licensed for use in Canada in 1998. It is given by needle, and is very safe. The side effects are temporary and usually mild. For example, some people have a sore spot or some tenderness where the needle went in. Up to 15% may have a mild fever that lasts for a few days. Up to 6% may develop a rash that resembles a mild case of chickenpox within a week or two of vaccination. The rash will clear up in about five days. Overall, these side effects are far less harmful than the potential complications from a serious case of chickenpox.
New Recommendations about Chickenpox Vaccine
The National Advisory Committee on Immunization (NACI) is a group of experts that provides Health Canada with ongoing and timely medical, scientific, and public health advice relating to immunization. In the 2002 Canadian Immunization Guide, NACI recommends the chickenpox vaccine for healthy children (age 12 months and up), teenagers, and adults who have not already had chickenpox.
If you have had chickenpox once, you do not need to get the vaccine. But, a dose of the vaccine is unlikely to cause any harm as long as your overall general health is good.
However, NACI advises that certain people should not get the chickenpox vaccine, including:
- people who have a prior history of severe allergic reaction to the vaccine, or other components of the vaccine
- people with weak immune systems, unless under the supervision of a specialist in infectious diseases
- pregnant women or those who are trying to get pregnant
- babies less than a year old
The cost of the chickenpox vaccine may or may not be covered by your health plan. Some provinces include it as part of their publicly funded immunization programs, while others have the matter under consideration.
Minimizing Your Risk
Obtain reliable information about chickenpox and chickenpox vaccine from credible sources. Talk to your doctor or health care provider about whether the chickenpox vaccine is right for you and your family.
Health Canada's Role
Health Canada regulates vaccines in Canada through a rigorous licensing process. This includes an extensive pre-market review of information about a vaccine's safety and effectiveness, and post-market assessment, such as tracking serious adverse reactions. In addition, Health Canada monitors and analyzes the incidence of vaccine-preventable diseases, develops guidelines for the control of diseases, and works with the provinces and territories on strategies to manage infectious diseases. Health Canada also participates in public awareness campaigns designed to help Canadians make informed decisions about immunization.
Need more info?
For more information about vaccines and the NACI recommendations, visit
 Public Health Agency of Canada's Immunization and Respiratory Infections Division
For the Canadian Immunization Guide, 6th edition, 2002
For related It's Your Health fact sheets on "Childhood Immunization," "Misconceptions about Vaccine Safety" and "Immunization Registries"
Other Web sites of interest include:
The Canadian Pediatric Society's "Caring for Kids" Web site
Canadian Coalition for Immunization Awareness & Promotion (CCIAP)
World Health Organization's Vaccines, Immunization Web site
U.S. Centers for Disease Control and Prevention's
National Immunization Program Web site
Additional It's Your Health articles
You can also call (613) 957-2991
İHer Majesty the Queen in Right of Canada,
represented by the Minister of Health, 2004
Original : January 2004
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